1. Field of the Invention
The present invention relates to a deoxyribo nucleic acid (“DNA”) detection device and a manufacturing method thereof, and more particularly, to a DNA detection device which detects DNA by an electrical method without any particular process for detection by using semiconductor microfabrication techniques, and a manufacturing method thereof.
2. Description of the Related Art
Generally, the possibility of discovering and treating human genetic diseases at an early stage from extensive DNA information and its expectations are growing. Hence, a DNA detection device is being established as another sensor in the field of biosensors.
In an attempt to directly detect DNA without performing a DNA deformation process, University of California, Santa Cruz (“UCSC”) in the U.S.A. devised a structure using alpha-hemolysin, which enables DNA detection without a separate detection process, such as DNA labeling.
In addition, using such characteristics as the electrical conductivity of a DNA double helical structure, a technique of electrically detecting DNA passing through a pore formed in a membrane on a solid semiconductor substrate was intensively devised in the late 1990's at Harvard and Princeton Universities, both in the U.S.A., and at Delft University, in the Netherlands.
FIG. 1 is a cross-sectional view showing a conventional DNA detection device developed at Delft University of the Netherlands.
As shown in FIG. 1, the conventional DNA detection device has a membrane 12 on a semiconductor substrate 10 in which a pore 11 is formed.
This DNA detection device is a device capable of detecting DNA passing through the pore 11 by applying a certain electrical signal to both ends of the pore 11.
However, such conventional DNA detection devices are manufactured one by one using ion beams after manufacturing the membrane 12 by forming an insulating film on the semiconductor substrate 10, thereby rendering the process complicated and the production difficult.
Moreover, it is inconvenient to handle the membrane 12 because of its thin thickness, and also difficult to detect a signal using measuring equipment because the dwell time during which DNA passes through the pore 11 is short, which imposes many limitations in detecting DNA smoothly.
To solve these drawbacks, another prior art DNA detection device that makes measurement easier by increasing the dwell time of DNA was devised by Omar A. Saleh and Lydia L. Sohn and is disclosed in Nano Letters, 2003.
FIG. 2 is a cross-sectional view of a conventional DNA detection device.
As shown in FIG. 2, the conventional DNA detection device includes a substrate 30 made of glass, an electrode 31 formed on the substrate 30, and an upper panel 40 made of synthetic rubber, for example, polydimethylsilixane (“PDMS”) having a projection.
The conventional DNA detection device has a structure in which a channel 50 is formed between the projection and the substrate 30 to detect a DNA 20 as an electrical signal from a detection sample infused between the substrate 30 and the upper panel 40.
However, the conventional DNA detection device has great difficulties in continuously producing the same structure because it is manufactured from synthetic rubber by using a mold master as a structural frame, formed by patterning SU8, which is a photoresist commercially available from Microchem Corporation, in an e-beam method.
However, the width of the channel formed 50 by the e-beam process is large, e.g., about 200 nm. Further, the method of adjusting the width of the channel 50 is restricted to the e-beam process, thus sustaining a difficulty in detecting an electrical signal of DNA passing through the wide channel, which fails to obtain a reliable result of DNA detection.